The front body structure of a vehicle is important for protecting occupants in frontal crashes. The integrity of a vehicle front body structure can be evaluated using crash tests, which involve a form of destructive testing usually performed in order to ensure safe design standards for various modes of transportation. There are different types of crash testing—administered in the United States by organizations including the National Highway Transportation Safety Administration (NHTSA) and the Insurance Institute for Highway Safety (IIHS)—for evaluating different aspects of a vehicle's crashworthiness. The most traditional crash test is known as a “frontal-impact crash test,” whereby a vehicle is driven to collide head-on with a barrier, such as a concrete wall. FIG. 1A illustrates an example frontal-impact crash test, in which the angle of impact directly opposes the direction in which the vehicle 100 travels. In this case, a load generated by colliding with the barrier 110 is experienced throughout the entire front end of the vehicle 100.
Meanwhile, in “overlap crash tests,” only part of the front end of a vehicle impacts a barrier. The impact force remains approximately the same as in a frontal-impact test, but a smaller fraction of the vehicle is required to absorb the force. In this regard, the IIHS developed a Small Overlap Impact (SOI) test, in which 25% of the front vehicle width strikes a rigid barrier 110 on the driver-side, as shown in FIG. 1B.
Unique challenges arise in protecting vehicle occupants in offset collisions. For example, if the longitudinal sidemembers on each side of the vehicle frame cannot fully absorb the kinetic energy of a front-end impact, the crash causes cockpit intrusion from wheel impact. Unfortunately, most modern unibody longitudinal sidemembers are inboard of the 25% overlap impact zone. Thus, the sidemembers cannot fully absorb the kinetic energy of such crash events.